Technical contribution to the soil load card

The Federal Soil Protection Act of 17 March 1998, the Federal Soil Protection and Contaminant Ordinance of 12 July 1999 and the Landesbodenschutzgesetz of 9 May 2000 bring new enforcement tasks, particularly at the municipal level. Digital soil pollution maps, which are drawn up by the municipalities and funded by the Ministry for the Environment and Nature Conservation, Agriculture and Consumer Protection of the State of North Rhine-Westphalia, can contribute to the fulfilment of these tasks. Digital soil load maps provide information about soils with naturally or anthropogenicly elevated pollutant levels, in some cases also about suspected areas and areas with harmful soil changes. In addition to organic pollutants, heavy metals are of particular interest. Heavy metals are partly vital trace elements, on the other hand they can develop harmful effects even in small amounts in plants, animals and humans. It is common to all that, unlike organic pollutants, they are not degraded in soils. In many landscapes, the heavy metal content of the upper soils exceeds not only those of the base rocks, but also the precautionary and limit values prescribed by the legislature. The Geological Service NRW provides the map of the heavy metal base contents of near-surface rocks as an evaluation of the digital soil map 1: 50,000 and the geochemical database. Data for the elements arsenic, lead, cadmium, chromium, copper, mercury and zinc are supplied. Up to now, approximately 42,000 data sets on heavy metal content in soils and rocks as well as the most important characteristics of the samples have been included in the geochemical database gestein.nrw. The data refer to 2,730 looser and solid rock samples from 1,176 sites in North Rhine-Westphalia and its peripheral areas. In addition, for each sample and sampling area, comprehensive information on the location, use, depth of collection, age, formation, soil and rock type, digestion and measurement methods are stored and thus accessible.